The present invention relates generally to exhaust treatment for an internal combustion engine and more particularly, but not exclusively, to a method, system, and software utilized to rapidly achieve an effective operating temperature of a diesel oxidation catalyst unit after engine startup.
The Environmental Protection Agency (“EPA”) is working aggressively to reduce pollution from new, heavy-duty diesel trucks and buses by requiring them to meet tougher emission standards that will make new heavy-duty vehicles up to 95% cleaner than older vehicles. Emission filters in the exhaust gas systems of internal combustion engines are used to remove unburned soot particles from the exhaust gas and to convert harmful pollutants such as hydrocarbons (“HC”), carbon monoxide (“CO”), and oxides of nitrogen (“NOx”) into harmless gases.
Exhaust gas is passed through a catalytic converter that is typically located between the engine and the muffler. In operation, the exhaust gases pass over a large surface area that is coated with a catalyst. A catalyst is a material that causes a chemical reaction to proceed at a usually faster rate without becoming part of the reaction process. The catalyst is not changed during the reaction process but rather converts the harmful pollutants into substances or gases that are not harmful to the environment.
Oxidation catalysts are known for use in treating the exhaust of diesel engines in order to convert gaseous HC and CO pollutants and particles by catalyzing the oxidation of these pollutants to carbon dioxide and water. Before these oxidation catalysts can function properly, the oxidation catalysts need to achieve a minimum operating temperature value. In order to provide for maximum conversion, the minimum temperature value needs to be reached as rapidly as possible following engine start up. Accordingly, there is a need for methods and systems for rapidly achieving an effective operating temperature of oxidation catalysts.